Breech mechanism



Dec. 6, 1938. H. LAUF BREECH MECHANISM Filed Sept. 16, 1936 2 Sheets-Sheet l HWS LAUF Jnre/rfaf: w Y@ ("Q" y Att omeq Dec. 6, 1938. H. LAUF 2,138,972

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Morneqs t Patented Dec. 6, 1938` UNITED STATES PATENT OFFICE 2,138,973 Bannon MECHANISM Hans Lauf, Berlin-Charlottenburg, Germany, as-v signor to Knorr-Bremse Aktiengesellschaft, Berlin-LichtenbergGermany -Y Y Application septemberls, 193e, serai No. 1'o1,1s1

Y v In Germany September 19, 1935 This invention relates to a breech mechanism.

for gas-Operated gull loaders.

casing members in whichthe sliding partsare guided. Frequent failures in the operation of the f loaders are the result of thisarrangement,` since?v the separate parts cannot besecuredjtogether'f so as to prevent slight displacement of the mem-g bers relative to one another, especially `Vafter. longer use of the gun. a Such relative displacement-1' 1 of the casing members usually' 'suicestogrend'en the loader inoperative-or seriously to ir'i'terfere! with proper working b of the same. more, in the breech mechanism of the usual '.type of gas-operated gun loaders the transmissionjof the forces released by a discharge -to"'the breech 'Furtheri common sleeve or casing which immovably iixes the relative position of the sliding parts, so that the troubles mentioned in operating the loader are completely eliminated. In the loader accord` ing to the invention the breech block is, moreover, locked in flring positionA in such a manner that the recoil produced by the discharge of a projectile is transmitted to the breech block without any tilting moment, whereby the life of the erably increased.

The breech mechanism. according to the invention is so constructed that the gas pressure prevailing inside the barrel during discharge causes the displacement of a spring-actuated articulated slide guided with the breech block in a single casing. The articulated slide is preferably connected with the breech block by an intermediate joint which converts the return motion of the articulated slide rst into a lifting motion of the breech block which is thus lifted out of locking rests engaged by lugs at the rear end of the block and which can then move rearwardly together with the spring-actuated articulated slide. The position of the connecting loader as well as safety in operation are considbreech only the articulated slide and the ring a i pinconnected therewith are moved at first while In the known gas-operated gun-Y loaders 'the b breech mechanism has a relativelycomplex con- 5' struction comprising; as a rule. two separate l the breech block remains in its position, since itlslifted onlywhen the upper fulcrumv of the connecting member has passed the vertical central plane extending through the lower fulcrum. Owingto this arrangement, the firing pin, during closing of the breech, is advanced only after lthe breechblockis in locking position so as to insure good reception of the explosion pressure produced by the discharge of a projectile.

V--The lspring-,actuated articulated slide is directly-connected with the iiring pin which is thus driven already at-the begining of the motion' of thel articulated slide while the breech block is stillv carrying outthe lifting motion. In case of f'misre, subsequent ignition is thus absolutely prevented, as `the iiring pin at the opening of the lock is the first part to be lifted off from the projectile. According to the invention, connection between the firing pin and the articulated slide is eected by means ofa guide groove provided in the klower part of the articulated slide and permitting up and down motion of the firing pin. The head of the ring pin is spherical so as to be able to roll over the lower rear wall of the articulated slide during up and down motion, whereby the connection between the firing pin and the slide is kept free from play. To permit upward motion of the breech block the portion of the breech casing, in which the breech block is positioned during discharge, is conically recessed in rearward direction.

Of special importance is the locking of the breech block in firing position, which is eifected, according to the invention, by means of three locking lugs, one of which is located on the underside of the breech block while the other two are arranged laterally of the block on a level with the axis of the bore. The particular advantage afforded by this arrangement is that at the moment of discharge the breech is positioned in the rectilinear extension of the axis of the bore, so that, owing to the locking on the underside and laterally on the level of the axis of the bore, stressing is possible only as to pressure and not as to bending. In this way, the development of a tilting moment, unavoidable in all known constructions, is effectively prevented. According to the invention, the lower locking lug is of the sliding type to guide the breech block and, when the breech is adjusted to single nre, simultaneously serves as catch for holding the breech block in open position.

A further advantage afforded by the breech according to the invention is that the firing pin on striking the primer is positioned in the rectilinear extension of the axis of the bore, whereby misme due to inaccurate or too low positioning of the primer in the projectile is avoided. f

The breech mechanism according to the invention is adapted for both single and continual fire by a corresponding adjustment of the releasing mechanism,so that at single fire the lower sliding lug catches behind the releasing mechanism and during continuous ring this lug can unobstructedly slide back and forward again. For manual operation of the breech a special lever is provided and connected with the articulated slide which can thus be drawn back by hand.

By way of example, the invention is illustrated in the accompanying drawings, in which Figure 1 shows the breech arranged on the rear part of the barrel with the breech block in locked position; Fig. 2 shows the breech in open position; Fig. 3 is a section on the line A--B, of Fig. 1; Fig. 4, a section on the line A-B, of Fig. 2; and Figs. 5 and 6 show the construction of the articulated slide the lower portion of which serves for the reception of the firing pin.

Referring to the drawings, and first to Fig. 1, the single breech casing 2 serves for guiding the articulated slide 3 subjected to the pressure of the spring 'I and the breech block I. 'I'he articulated slide 3 is controlled by the gas pressure inside the barrel'by means of the rods 4 which are moved by gas pressure in any suitable manner, for instance by the interposition of a piston. Connection between the articulated slide 3 and the breech block I is established by a connecting joint 5 which, as shown, is arranged in such manner that in firing position the upper fulcrum thereof leads with respect to the lower fulcrum thereof in the direction of the muzzle. Inside the breech block I a firing pin 6 is disposed and directly connected with the articulated slide 3 which, as shown in Figs. 5 and 6, possesses in its lower part a guide groove for receiving and guiding the firing pin 6. The firing pin 6 bears with its collar against the guide groove and has a spherical head so as to be able to roll over the lower portion of the rear wall of the articulated slide 3. As indicated in Fig. 1, the firing pin 6 is positioned in the rectilinear extension of the axis of the bore at the moment of discharge. 'Ihe arrangement of the locking lugs 8, I0 is shown in Fig. 3 and corresponds to the position of the breech block during the discharge. The corresponding position for the opened breech is shown in Fig.4. Fig.2 shows the opened position of the breech block when the weapon is adjusted to single fire. As indicated in this figure, the sliding lug I0 catches at the extreme right-hand position of the ring pin 6 behind the releasing device.

The breech mechanism according to the invention operates as follows:

Thepressure of the gases of explosion causes the control member 4 shown in Fig. 1 to be moved to the right and thereby drives the articulated slide 3, the connecting joint 5 and the firing pin 6. After the upper fulcrum of the connecting joint 5 has passed the vertical central plane extending through the lower'fulcrum the lifting motion of the breech block begins, whereby the locking lugs are lifted out of their respective rests, so that the breech block I together with the articulated slide 3 moves towards the right. When the breech block I has reached its extreme right-hand position, the sliding lug I0 catches behind a corresponding projection of the releasing mechanism and the breech is kept in opened position. When release is effected. the operations described are repeated in reverse order. The breech block I, in response to spring pressure, rapidly advances until the locking lugs engage again their respective rests. Only after the descent of the breech block is completed and the block has been locked is the firing pin advanced to e'ect ignition. This mode of operation corresponds to the adjustment of the weapon to single ilre. In continuous firing the sliding lug I0 in rearward position does not meet a projection behind whichit could catch and therefore unobstructedly slides forward again.

I claim:-

1. A breech mechanism for automatic rearms, comprising a tiltable breech block, locking means on said block, a spring-controlled slide, a common casing containing said block and slide, a rod connected to said slide, said rod controlling said slide in response to gas pressure, joint means.

between said breech and slide for converting the rearward motion of said slide into a lifting motion of the breech block to release said locking means, a firing pin within said breech block, said pin being connected to said slide, the motion of the slide starting the withdrawal of said firing pin before lifting said block, said joint means comprising pivotal connections on said slide and on said breech, the upper fulcrum of said means being situated before the lower fulcrum thereof in its forward position when said breech block is in locking position, second locking means adapted to catch said block behind a releasing mechanism in the rearward position of said block, and groove means on said slide for receiving and guiding the head of the firing pin on the longitudinal axis of said pin.

2. A breech mechanism for automatic firearms, comprising a tiltable breech block, locking means on said block, a spring-controlled slide, a common casing containing said block and slide, a rod connected to said slide, said rod controlling said slide in response to' gas pressure, joint means between said breech and slide for converting the rearward motion of said slide into a lifting motion of the breech block to release said locking means, a firing pin within said breech block, said pin being connected to said slide, the motion of the slide starting theA withdrawal of said firing pin before lifting said block, said joint means comprising pivotal connections on said slide and on said breech, the upper fulcrum of said means being situated before the lower fulcrum thereof in its forward position when said breech block is in locking position, second locking means adapted to catch said block behind a releasing mechanism in the rearward position of said block, and groove means on said slide for receiving and guiding the head of the firing pin on the axis of said pin, said head being spherical.

3. A breech mechanism for automatic firearms, comprising a tiltable breech block, locking means on said block, a spring-controlled slide, a common casing containing said block and slide, a rod connected to said slide, said rod controlling said slide in response to gas pressure, joint means between said breech and slide for converting the rearward motion of said slide into a lifting motion of the breech block to release said locking means, a firing pin within saidbreech block, said pin being connected to said slide, the motion of the slide starting the withdrawal of said firing pin before lifting said block, said joint means comprising pivotal connections on said slide and on said breech, the upper fulcrum of said means being situated before the lower fulcrum thereof in its forward position when said breech block is in locking position, said locking means comprising two locking lugs on said block for coaxially and bilaterally locking said block on the level of the axis of the barrel, second locking means adapted to catch said block behind a releasing mechanism in the rearward position of said block, and groove means in said slide for receiving and guiding the head of the firing pin on the longitudinal axis of said pin.

4. A breech mechanism for automatic firearms, comprising a tiltable breech block, locking means on said block, a spring-controlled slide, a common casing containing said block and slide, a rod connected to said slide, said rod controlling said slide in response to gas pressure, joint means between said breech and slide for converting the rearward motion of said slide into a lifting motion of the breech block to release said locking means, a ring pin within said breech block, said pin being connected to said slide, the motion of the slide starting the withdrawal of said ring pin before lifting said block, said joint means comprising pivotal connections on said slide and on said breech, the upper fulcrum of said means being situated before the lower fulcrum thereof in its forward position when said breech block is in locking position, said locking means comprising two locking lugs on said block for coaxially and bilaterally locking said block on the level of the axis of the barrel, a. third locking lug provided on the underside of said block and serving first during withdrawal of the breech block as a guide lug and secondly as a locking means for said block behind a releasing mechanism, and groove means in said slide for receiving and guiding the head of said pin on the longitudinal axis of said pin.

5. A breech mechanism for automatic firearms comprising a breech casing, a breech block tiltably contained within said casing, a firing pin axially mounted Within said breech block, a return spring and slide coaxially mounted in firing position with respect to said breech block and firing pin, said block, pin, spring, and slide being adapted and arranged to resist axially the firing gas pressure without being subjected to bending stresses, locking means for said breech block while said block is in firing position, and means to tilt said breech block out of locking position. 6. A breech mechanism for automatic firearms comprising a barrel, a breech casing, a breech block, firing pin, and return spring mounted in axial alignment with said barrel, means for locking said block, pin, and spring in said axial alignment with said barrel during firing of said firearm, a gas piston operated slide, means connecting said slide to said block to tilt said block out of locking engagement with said casing upon movement of said slide, said pin being in continuous axial alignment with said block, and means connecting said pin and said slide. l

HANS LAUF. 

